| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| 2 | /* |
| 3 | * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk> |
| 4 | */ |
| 5 | #ifndef _DCCP_CCID2_H_ |
| 6 | #define _DCCP_CCID2_H_ |
| 7 | |
| 8 | #include <linux/timer.h> |
| 9 | #include <linux/types.h> |
| 10 | #include "../ccid.h" |
| 11 | #include "../dccp.h" |
| 12 | |
| 13 | /* |
| 14 | * CCID-2 timestamping faces the same issues as TCP timestamping. |
| 15 | * Hence we reuse/share as much of the code as possible. |
| 16 | */ |
| 17 | #define ccid2_jiffies32 ((u32)jiffies) |
| 18 | |
| 19 | /* NUMDUPACK parameter from RFC 4341, p. 6 */ |
| 20 | #define NUMDUPACK 3 |
| 21 | |
| 22 | struct ccid2_seq { |
| 23 | u64 ccid2s_seq; |
| 24 | u32 ccid2s_sent; |
| 25 | int ccid2s_acked; |
| 26 | struct ccid2_seq *ccid2s_prev; |
| 27 | struct ccid2_seq *ccid2s_next; |
| 28 | }; |
| 29 | |
| 30 | #define CCID2_SEQBUF_LEN 1024 |
| 31 | #define CCID2_SEQBUF_MAX 128 |
| 32 | |
| 33 | /* |
| 34 | * Multiple of congestion window to keep the sequence window at |
| 35 | * (RFC 4340 7.5.2) |
| 36 | */ |
| 37 | #define CCID2_WIN_CHANGE_FACTOR 5 |
| 38 | |
| 39 | /** |
| 40 | * struct ccid2_hc_tx_sock - CCID2 TX half connection |
| 41 | * @tx_{cwnd,ssthresh,pipe}: as per RFC 4341, section 5 |
| 42 | * @tx_packets_acked: Ack counter for deriving cwnd growth (RFC 3465) |
| 43 | * @tx_srtt: smoothed RTT estimate, scaled by 2^3 |
| 44 | * @tx_mdev: smoothed RTT variation, scaled by 2^2 |
| 45 | * @tx_mdev_max: maximum of @mdev during one flight |
| 46 | * @tx_rttvar: moving average/maximum of @mdev_max |
| 47 | * @tx_rto: RTO value deriving from SRTT and RTTVAR (RFC 2988) |
| 48 | * @tx_rtt_seq: to decay RTTVAR at most once per flight |
| 49 | * @tx_cwnd_used: actually used cwnd, W_used of RFC 2861 |
| 50 | * @tx_expected_wnd: moving average of @tx_cwnd_used |
| 51 | * @tx_cwnd_stamp: to track idle periods in CWV |
| 52 | * @tx_lsndtime: last time (in jiffies) a data packet was sent |
| 53 | * @tx_rpseq: last consecutive seqno |
| 54 | * @tx_rpdupack: dupacks since rpseq |
| 55 | * @tx_av_chunks: list of Ack Vectors received on current skb |
| 56 | */ |
| 57 | struct ccid2_hc_tx_sock { |
| 58 | u32 tx_cwnd; |
| 59 | u32 tx_ssthresh; |
| 60 | u32 tx_pipe; |
| 61 | u32 tx_packets_acked; |
| 62 | struct ccid2_seq *tx_seqbuf[CCID2_SEQBUF_MAX]; |
| 63 | int tx_seqbufc; |
| 64 | struct ccid2_seq *tx_seqh; |
| 65 | struct ccid2_seq *tx_seqt; |
| 66 | |
| 67 | /* RTT measurement: variables/principles are the same as in TCP */ |
| 68 | u32 tx_srtt, |
| 69 | tx_mdev, |
| 70 | tx_mdev_max, |
| 71 | tx_rttvar, |
| 72 | tx_rto; |
| 73 | u64 tx_rtt_seq:48; |
| 74 | struct timer_list tx_rtotimer; |
| 75 | struct sock *sk; |
| 76 | |
| 77 | /* Congestion Window validation (optional, RFC 2861) */ |
| 78 | u32 tx_cwnd_used, |
| 79 | tx_expected_wnd, |
| 80 | tx_cwnd_stamp, |
| 81 | tx_lsndtime; |
| 82 | |
| 83 | u64 tx_rpseq; |
| 84 | int tx_rpdupack; |
| 85 | u32 tx_last_cong; |
| 86 | u64 tx_high_ack; |
| 87 | struct list_head tx_av_chunks; |
| 88 | }; |
| 89 | |
| 90 | static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hc) |
| 91 | { |
| 92 | return hc->tx_pipe >= hc->tx_cwnd; |
| 93 | } |
| 94 | |
| 95 | /* |
| 96 | * Convert RFC 3390 larger initial window into an equivalent number of packets. |
| 97 | * This is based on the numbers specified in RFC 5681, 3.1. |
| 98 | */ |
| 99 | static inline u32 rfc3390_bytes_to_packets(const u32 smss) |
| 100 | { |
| 101 | return smss <= 1095 ? 4 : (smss > 2190 ? 2 : 3); |
| 102 | } |
| 103 | |
| 104 | /** |
| 105 | * struct ccid2_hc_rx_sock - Receiving end of CCID-2 half-connection |
| 106 | * @rx_num_data_pkts: number of data packets received since last feedback |
| 107 | */ |
| 108 | struct ccid2_hc_rx_sock { |
| 109 | u32 rx_num_data_pkts; |
| 110 | }; |
| 111 | |
| 112 | static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk) |
| 113 | { |
| 114 | return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid); |
| 115 | } |
| 116 | |
| 117 | static inline struct ccid2_hc_rx_sock *ccid2_hc_rx_sk(const struct sock *sk) |
| 118 | { |
| 119 | return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid); |
| 120 | } |
| 121 | #endif /* _DCCP_CCID2_H_ */ |